A survey by the Washington-based Governing magazine last week found that more chambers could change party hands in 2010 than in any other election cycle since at least 2002. Although more than 20 Democrat-controlled state chambers are in play, Republicans are in jeopardy of losing just four.

Other surveys show Republican gubernatorial candidates looking strong in many states, increasing the chance of a major shift in the balance of power in state-level politics heading into the 2012 presidential election.

The party in the White House usually loses seats at the state level in midterm elections.

According to the National Conference of State Legislatures (NCSL), the White House party has been a net loser of state legislative seats in every election in the past 110 years except 1934 and 2002, the first midterm elections of Presidents Franklin D. Roosevelt and George W. Bush, respectively.

That dynamic, combined with voter concerns about the economy, federal spending and Democratic control of 55 percent of state seats means 2010 is "shaping up to be the worst election for Democrats since 1994," said the NCSL's Tim Storey.